1. Field of the Invention
The present invention concerns a rear-view mirror system with display device in which a rear-view mirror for obtaining a rearward view of a car is held in a mirror housing, and a display device for displaying information different from that of the rearward view obtained at the rear view mirror is attached to a rear-view mirror device disposed in a car room.
2. Description of the Related Art
Rear-view mirror systems disposed in a car room and provided with a display device such as for televisions, clocks, images behind car upon rearward movement of the car, and navigation system have been known so far. Japanese Unexamined Utility Model Publication No. 54-33550 discloses a system in which a display device is disposed to the outer lateral side of a rear-view mirror and Japanese Unexamined Patent Publication No. 08-175263 discloses a display device including a display window disposed on a plane identical with that of the rear-view mirror, an emission display device disposed in a mirror housing and an information display mirror that reflects emission information from the emission display device and transmits the same through the display window.
However, in the system disclosed in the JM-A No. 54-33550, since focal points are different between images displayed on the rear-view mirror (far images) and images displayed on the display device (near images), (1) this obliges a car driver not only to transfer the line of sight but also adjust the focal distance of eyes and (2) a display device of high luminance to ambient light is required since the display device is exposed to the outside, and this increases the consumption current and increases the amount of heat generation.
On the other hand, in the system disclosed in JP-A No. 08-175263, the problems in (1) and (2) above can be solved. However, since the display window is disposed being adjacent with the rear-view mirror or the display window is formed to a portion of the rear-view mirror and the rearward view obtained at the rear-view mirror is narrowed, this hinders the visibility for the rearward view. Further, in a case of forming the display window to a portion of the rear-view mirror, it discloses a method of making the reflection film of the rear-view mirror with a total reflection film and cutting out a portion of the total reflection film to form a display window, a method of forming the reflection film of the rear-view mirror with a translucent reflection film and a black color coating film and cutting out a portion of the back color coating film to form a display window, and a method of making only the portion of the reflection film of the rear-view mirror that corresponds to the display window as a translucent reflection film and making a remaining portion as a total reflection film. However, in a case where the translucent reflection film is present for a portion of the rear-view mirror corresponding to the display window, since emission display information reflected on the information display mirror has to transmit the translucent reflection film, it needs an emission display device of high luminance, and this increases the consumption current and increases the mount of heat generation.